In this episode Paris claims that Humans gave up smoking centuries ago. So why did the transporter room have a "No Smoking" sign in "Star Trek III: The Search For Spock"?

Great Moment :

The concept of a punishment involving reliving the crime from the victim's point of view is a rather interesting one, I thought.

Body Count :

One, the alien scientist guy. We don't see it in the episode, but we do see it in the flashback - though that turns out to be false.

Factoid :

Ex Post Facto is latin for "from after the action", referring to laws designed to punish crimes that happened before the law was enacted. Such laws are illegal in many countries as they make it effectively impossible to be a law abiding citizen.

Plotline

We open with Tom Paris in a nasty predicament on an alien planet. He has been convicted of murder and received a horrific sentence - every fourteen hours he must relive the memory of the murder from the victim's point of view. Ensign Kim returns to Voyager with the news. The two had been sent to the Banean homeworld where they stayed with Tolen Ren, a physicist, and his beautiful wife Lidell. Tom found Lidell very attractive, despite her married status, and she returned the feeling. When Tolen discovered the relationship he confronted Tom angrily, and was soon after found stabbed to death in front of his wife. Both Lidell's testimony and an examination of Tolen's last memories via a technology the Baneans posses show Tom as the killer.

Janeway takes Voayger to the Banean homeworld to investigate. Tom denies any guilt for the crime, but the Baneans think it is an open and shut case. After he next relives the crime Tom collapses, and the authorities agree to allow him back to Voyager for a medical exam. In orbit Voyager is attacked by a Numiri ship. The Numiri are enemies of the Baneans and are said to be a violent, short tempered people. Voyager is able to fight off the attack. In sickbay Tuvok mind melds with Tom so that he can witness the memories of the crime himself. As a result of this and interviews on the planet, Tuvok is able to crack the case.

He reveals to the Baneans several important pieces of evidence; most notably the memories implanted in Tom have been tampered with, since they show Tom to be the same height as Lidell when in truth he is significantly taller. An alpha numeric code is also present in the memories, something Tom took to be a normal element of the technology but which are in fact coded secret information. He also points out that the killer stabbed Tolen in just the right place to kill him, something unlikely for Tom as he would not know Banean anatomy. Tuvok concludes that the implanted memories were falsifies and secret information from Tolen's weapons research added to them. The plan was for the Numiri to abduct Tom later on, explaining their attack on Voyager. Only the doctor who performed the memory implant on Tom would have the ability to manipulate it, so he must logically be the killer. Tom's treatment is reversed and he is freed to continue on his way with the ship.

Analysis

Really not the best of episodes. It's a stab at a sci fi whodunnit, and a few elements of it are interesting, but it's just bogged down by nonsense. The point of a whodunnit is to dangle clues that are subtle enough for the audience to miss. Ideally, when the killer is revealed, the audience should have a "why, of course! Why didn't I think of that!" moment. And indeed the bit about the different heights is good in that respect. But the number code implanted in the memories really, really is not. We don't know about this technology, so when the reveal happens the most we can do is "well... okay." It's like having a whodunnit where at the end they say "And I can reveal that the killer is Professor Plum, which I know because I did a special new forensics test when I first got here and it showed he did it." If the solution turns out to be a piece of information that the audience is never given and has no way to understand, then how can the response possibly be anything but "Oh... well okay then." Similarly the stab wound being right into a particular vulnerable spot over the heart - how can we possibly be expected to think this is clever when we have no idea where a Banean's heart is until Tuvok says he was stabbed there, right at the end? It's just stupid!

And the clincher to all this, the real damning piece of evidence, is an eyewitness identification... by a dog! A DOG!

It's an incredible combination of clues that are outright stupid with ones that just leave us completely in the dark and completely unengaged.

There's also one of my pet peeves. The line : "Smoking is a bad habit. My species gave it up centuries ago when we finally got it into our heads it was killing us." Really? Seriously, every single last human alive made that collective decision, did they? What an incredible world the future is, where every single person alive thinks exactly the same way about every substantive issue. I get that Star Trek writers want to show a future where tastes have changed, and that's fine. Things DO go out of fashion, things do die out and recede into history. For example, I have no problem with the way Trek depicts baseball as dying out, because the way they tell it, the game simply declined in popularity until the leagues folded, and finally nobody played any more. But they did switch to new games - Parrises squares for example (which, despite the fact that it kills players quite regularly, including small children, "we" remain perfectly fine with). One only needs to look at history to see that games do go in and out of fashion. And yet such things do tend to survive, on a small basis, just as Baseball survives on a small basis in the future with the Niners and other small teams. But so often the slide into this smug "well, we decided that..." trope. It creates this mental image that the whole of humanity gets together once a year and decides which hobbies and interests people can enjoy. "Well to summarise then, humanity has given up on the colour red. We've decided that our favourite colour is blue. Also, we like Mexican food and Wednesday is our favourite day of the week. And, we all vote Democrat."